Sanitary pipette.



.RlHOIVISTEAll SANITARY PIPETTE.

APPLICATION FILED IuNI;- I2, 1917.

Patented jan. 1,1918;

ATTORNEY WIISOlllB. HOMSTEAD, OF CARMEL, MAINE.

SANITARY PIPETTE.

Speeication of Letters Patent.

Patented dan. 1, 1918.

Application led J une 12, 1917. Serial No. 174,333.

To all lwtom. it may concern.'

Be it known that I WILSON R. HoMs'rmD, a citizen of the United States, residing at Carmel, in the county of Penobscot and State of Maine, have invented new and use ful mprovements in Sanitary Pipettes, of which the following is a specification.

This invention relates to measuring or testing vessels of the ipette type, and has for its object to provi e a pipette of a samtary construction which obviates the objections to ordinary devices of this class, so that the same may be used with absolute safety and without detriment to the health of the operator.

I accomplish these objects and others by a novel construztion, a satisfactory embodiment.` of which is illustrated by the accom' panymg drawings.

In the drawings,

Figure 1 is a side elevation of a yplpette constructed in accordance with the present invention.

Fig. 2'is a simple longitudinal sectional view through the same, illustrating the manner in which the air pressure from the bulb is regulated by the thumb or linger of the operator.

Fig. 3 is a detail, approximately central vertical longitudinal sectional view through the neck portion of the device taken at a right angle to the construction illustrated in In the drawings, the pipette is broadly indicated by the numeral 10, the same comprising the usual enlarged chamber 11 having both the inlet and discharge tube 12 communicating with one end of the chamber 11, while a neck 13 communicates with the other end of the saidchamber 11. The neck 13 is provided with the usual graduations 14 and the end of the said neck is preferably flared outwardly as indicated by the .numeral 15.

The neck 13 from the flared mouth thereof is provided with a partition-16, the inner end of which is connected, as at 17, to one of the walls of the neck 13, and the said wall is provided with an orifice 18. The partition 16 preferably terminates a slight distance below'the mouth 15 .of the neck'13, the said partition, at its said end,`however, being centrally depressed as at 19 and this depression provides a communication between the passages 20 and 21 provided in the neck by the partition 16. The passage 20 communicates with the orifice 18, while the passage 21 communicates directly with the chamber 11, the partition being of a wldth corresponding to the cross sectional diameter of the bore of the neck 13.

Arranged upon the neck 13 is a compress1ble bulb 22, the said bulb inclosing the orlice 18 andthe operation of the device may be briefly described as follows The linger of the operator, as illustrated in Fig. 2 of the drawings, is arranged over the mouth 15 of the neck 13 so that when the finger contacts with the outer end 19 of the partition 18, the passages 20 and 21 will be closed to each other. The bulb is compressed and the operator by regulating the pressure of his finger upon the mouth of the neck, regulates the amount of air passlng from thepassage 20 through the passage 21, so that in reality, his lingers serve as a valve, and by regulating the air pressure, by compressing` the bulb 22 the inflow and exhaust of the liquid can be properly controlled without in any way endangering the health of the operator.

The operators finger is first arranged lightly over the mouth 15 of the neck and the bulb 22 compressed to expel the air from the' vessel. The lower end of the tube 12 is then dipped into the liquid to be measured or tested, and the pressure of the bulb 22 is gradually diminished so as t0 allow the solution to rise up into the vessel to the desired gage mark upon the neck 13, thereafter the operator rmly presses his finger against the mouth 15 of the neck to close the communication between the passages 20 and 21. After the liquid has been drawn into the vessel by this mode of operation, accuracy of measurement may be obtained by bringing the bottom of the meniscus to a levelwith the graduation or gage mark by a gentle movement of the thumb of the operator over the'end 19 of the partition 16 to gradually open communication between the passages 20 and 21, a slight pressure being 'ven to the bulb 22. In this manner the 4liquid may be readily and conveniently drawn into the tube andv gaged in a sanitary manner and by proper manipulation of the bulb and the linger of the operator, the device may be controlled to awhighly sensitive degree. The liquid may be discharged by v the removal of the finger of the operator from contact with the end 19 of the partition 1 6 and the operation of the bulb 22, as will be rea filly understood.

Having thus described the invention, what I claim is:

1. In a pipette, a member comprising a chamber, a combined inlet and dischar e tube communicating with one of the en s of the chamber, a graduated neck formed upon the opposite end of the chamber and having an outwardly flared mouth, of a partition in the neck having its inner vend connected with one of the walls of the neck whereby to divide the neck into two passages, said neck having an opening communieating with one of the passages, and a compressible bulb upon the neck and inclosing the o ening.

2. combination with a pipette compris- 1 ing a chamber, a combined intake and discharge tube communicating with the lower end ofthe chamber, a. relatively short neck of a greater diameter than the tube communicating with the upper end of the chamber,.said tube having ga e marks and having its ends flared ontwardl,1 of a partition in the neck having its lower `end connected with one of the sides of the neck, said neck having an opening arranged above the connec- -tion of the partition therewith, said partition WILSON R. HOMSTEAD. 

